Machine tool



R. l. MARTIN MACHINE TOOL. Filed Aug. 14,1951.

4 Sheets- Sheet 1 R. I. MARTIN MACHINE TOOL Filed Aug. '14, 1931 Oct. 1, 1935.

4 Sheets-Sheet 2 e Patented; Oct. 1, 1935 UNITED STATES PATENT OFFICE 2,015,685 I MACHINE TOOL Ray LMartin, Dayton, Ohio, assignor, by :ncsnc assignments, to The Cimatool Company, Dayton, Ohio, a corporation of Ohio Application August 14, 1931, Serial No. 556,970 5 Claims. (01. 77-3) sion of a machine tool comprising a stationary work receiving member having a rotatable tool relatively thereto for rapid and accurate operation on a work piece while releas-ably held by the work receiving member.

Another object of the invention is the provi- 20 sion of a machine tool comprising non-rotatable work receiving means accurately held in stable position and having spaced rotatable tool carrying spindles associated therewith which are axially movable to traverse a cycle of operation in 25 which the paths of travel of the tools are definitely and accurately related.

A further object of the invention is the provision of a machine tool having a tool carrier comprising but fewparts and providing a substantial support for a tool bit which is movable in controlled amounts through minute steps of adjustment.

Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.

carrying spindle mounted therein and movable In the drawings, which illustrate a preferred embodiment of the invention Fig. 1 is a side elevational view of a machine tool constructed in accordance with this invention; 1

Fig. 2 is a sectional view taken on theline 2-2 of Fig. 1;

Fig. 3 is a sectional view taken on the line 33 of Fig. 2;

Fig. 4 is a detail view of the operating control;

Fig. 5 is a sectional view taken on the line 5-5 of Fig. 2;

Fig. 6 is a sectional view taken on the line G of Fig. 5;

I Fig. 7 is a vertical sectional view of a portion of the spindle driving and feeding mechanism;

Fig. 8 is a sectional view taken on the line 88 of Fig. 1;

Fig. 9 is a sectional view taken on the line 3-9 of Fig. 8; and

Fig. 10 is a sectional view taken on the line Ill-l0 of Fig. 9. I w

The. drawings, in which like characters of ref- 5 erence designate like parts throughout the several views thereof, illustrate a machinetool for boring spaced concentrically related holes with rapidity and extreme precision. As shown, the machine comprises generally a bed or base I0 10 upon which are mounted spaced work receiving members or chucks II and I2. The chucks stand facing one another and are definitely located in alignment within. the cylindrical bore ll of a Y drum l5 which is securely fixed to the machine bed by provision of bolts I 6. The chuck II' and its associated mechanism are fixedlymounted to the machine bed while the chuck l2 and its associated mechanism, although non-rotatable,

may be moved axially. Each of the chucks has mounted therein a tool spindle assembly l8 which carries a rotatable boring tool 20. Each tool 20 is accurately positioned centrally of the cylindrical outer surface 2| of its spindle assembled l8, and each spindle assembly in turn is securely held within its chuck in a cylindrical bore 22 which is accurately positioned concentrically of the exterior cylindrical peripheral wall 23 of that chuck. The chuck walls 23 are a close fit within the bore of the common drum [5 so that the 80 tools 20, although supported within portions of y the machine which are spaced apart, are accurately held in alignment upon a common axis. The drum I5 is provided with a side opening 25 for access to the chucks. Each of the chucks is provided with a number of radially movable jaws 21 which may be actuated to engage a work piece for operation by the tools 20.

In the illustrated embodiment of the invention the work piece is shown in the form of a cluster gear 30 such, for example, as is used in an auto mobile transmission. The cluster gear 30 comprises a cylindrical hub portion 3| which has formed at'each end a spur gear 32. Each end of the hub has seated within it a cylindrical sleeve 33 which serves as a bearing for rotation of the gear when assembled in the structure of which it is to form a part. This machine provides a means of taking an accurate finishing cut from the face of both bushings 33 simultaneously, and

the construction of the machine is such that although the finishingcuts are made by independenttools, the resulting finished surfaces are accurately aligned to a very high degree of precision.

Each of the chucks has attached to it an axially extending tube 35 which is shown attached thereto by the bolts 36. The opposite end of each of these tubes has attached to it a housing 31 which serves as an enclosure for the mechanism by which the tool spindles are driven and are moved axially. The fixed chuck ll, its tube 35 and housing 31 form a unit which is rigidly held to the machine bed by suitable bolts which extend from the bed into the housing 31, and into the supporting leg 38 which is an integral extension of the chuck tube 35. The movable chuck l2, its tube 35 and attached housing 31 form a unit which is slidably attached to the machine bed. This. unit is further supported by a block 39 which is rigidly attached to the bed and which engages the tube surface in such a manner as to permit axial sliding movement of the tube. The housing 31 of the chuck I2 is supported from the bed l8 upon a bracket 40 which is guided within ways 4| of the base In.

Each of the-chucks is provided with a body portion 43 to which the tube 35 is attached, and each body portion is provided with suitable guide means for reception of the chuck jaws 21. These jaws have an inner face. in the form of cylindrical segment 44 by which the work piece is engaged, and an outer tapered face 45 for engagement with a jaw actuating mechanism. The jaw actuating mechanism of each chuck is in the form of an axially movable cylindrical sleeve 44 of which the outer peripheral surface forms the exterior surface 23 of the chuck. The inner surface of this sleeve is cylindrical for a portion of its length, as indicated at 46, for sliding engagement with the outside peripheral rim of the chuck body while an adjacent portion 41 is of conical form for engagement with the ends 45 of the chuck jaws 21. Upon axial movement of the sleeve 44 the jaws 21 are caused to move radially by engagement with the conical face 41.

Hydraulic cylinders are provided for actuation of the sleeves 44 and are shown as comprising cylinders which are suitably supported by brackets 5| which are attached to plate extensions 52 of the tubes 35. The movable piston of each cylinder has a projecting rod 53 which is pivotally connected to a bell crank 54 that is supported upon an axle pin 55 carried by the bracket 5|. The opposite end of the bell crank is of yoke like shape and has pivotally connected to each leg of the yoke a link 56; each of which is in turn pivotally connected to a clevis 51 which the movable chuck I 2 and the bore of the drum l5.

The chuck jaws 21 are constantly urged outwardly to a position of release by provision of spring pressed plungers 62 having conical ends 63 which engage a V-shaped notch 64 of each chuck jaw. The respective positioning of notch and pin is such that when the actuating sleeve 44 moves in the direction to force the jaws inwardly to engaging position, the pin 62 is caused to move in a direction to compress the spring 65' and so-tension the jaw in such a manner that upon movement of the sleeve in the opposite direction each jaw will be caused to move outwardly.

Each tool spindle assembly l8 comprises a tubular spindle bar supporting member 68 which is received within the tube 35 and is closely held within the cylindrical bore 22 of the associated chuck. The adjacent ends of the oppositely positioned spindle assemblies are accurately held in alignment by being closely held in the chucks which in turn are closely held in ,the common drum l5. The remote ends of the spindle assem blies, although loosely received within the tubes 35, are rigidly held therein by provision of adjusting screws which permit angular adjustment of the spindle axes so that the spindles may be readily moved into accurate axial alignment. The adjusting screws 66, which threadedly engage the tubes 35, are shown spaced 90 degrees apart, and positioned to engage the end of each spindle assembly opposite to that which is held in the chuck bore 22. A shouldered brass pin 61 is positioned intermediate each screw and the spindle assembly and serves as a clamping means upon drawing tight its associated screw. These tubes 68 are securely held stationary with respect to the chucks. As shown, axial movement of each tube 68 is prevented in one direction by provision of a stop lug 69 which extends inwardly from the face 22 for engagement against the end of the tube 68. Rotation-of the tube 68 relatively to the chuck and movement in the opposite direction is prevented by provision of a screw 10 which threadedly engages the chuck body 43 and has a head portion H which overlies and is received within a notch '12 of the tube 68. A concentrically related sleeve 15 is mounted within the tube 68 and is supported therefrom upon ball bearings 16 and 11. This sleeve 15 has a longitudinally extending cylindrical bore the feeding and driving forces are transmitted 4 to the bar 86.

This bar 86 is of considerable length, is hardened, and is of uniform diameter throughout its length. The bar is a. sliding fit within the accurately lapped cylindrical bore of the sleeve 15; the fit being such that the bar may inove axially with respect to the sleeve but without any side play.

Means are provided whereby the bar 89 may move axiallywith respect to the sleeve 15 while being connected thereto in such a manner that the sleeve is caused to rotate with the bar. As shown, the bar 86 is provided with diametrically opposite longitudinally extending grooves 81 formed in the cylindrical outer wall thereof. The sleeve 15 has formed therein diametrically opposite and aligned openings 86 within which are positioned tubular guides 89. These guides serve to hold spherical balls 98 so tliatthey are received within the grooves 81. The balls 98 are held against radial movement by provision of a block 9| positioned within each tube 89 behind the ball 90 and maintained in place by a plug 92 which closes each opening 88; the plugs 92 being held in position by cross pins 93.

The rear end of the tube 68 carries a ball bearing 95 which supports a sleeve 96 that slidably engages the driving member 84 and serves to accurately align this member with respect to the adjacent end of the bar 80 to which it is connected by provision of the flexible coupling 83.

' of the overflow fitting I02.

As shown, this coupling is in the form of perpendicularly related dove tailed joints having a spacing ball 91. This coupling, although serving to transmit driving and feeding movements to the spindle bar 80 permits a certain freedom of movement between the parts 80 and 84 so that any forces tending to disturb the balance of the rapidly rotating bar 80 will be absorbed in the coupling and will not be transferred to the tool carrying bar 80. Accurate machining of the several parts, together with the provision of ample bearing surfaces between those parts that move relative- 1y to one another results in a sturdy structure wherein accurate alignment may be maintained between the rapidly rotating spindle and its associated stationary chuck so that the boring tool will traverse a path concentrically related to the work holding position of the chuck jaws.

To provide for lubrication of the spindle parts a drilled opening I extending through the tubes 35 and 68 provides communication between an oil cup IOI and the interior of the spindle. Oil supplied through this cup I M fills the space within the tube 68 to a level controlled by the height Oil escape at the ends of the tube 68 is prevented by suitable oil tight glands adjacent the tube ends as indicated at I04. The oil contained within the tube 68 may readily flow to the ball bearings 16, 11, and 95, and is supplied to the contacting bar and sleeve surfaces by provision of scoops I 05. These scoops comprise projections I06 extending radially from the outer surface of the sleeve 15; drilled holes I01 providing communication between each scoop and the interior of the sleeve. Oil passing through the holes I01 is caused to traverse the length of the interengaging bar and sleeve faces through the grooves 81, from which it is further distributed by provision of an annular groove I08 on the inner face of the sleeve 15. Very little lubricant can escape from the tool carrying end of the bar 80 due to the extremely close running fit between the bar and sleeve.

Rotational movement of each spindle I8 is provided by an independent driving motor IIO mounted upon each housing 31 and connected to its respective spindle by a belt drive I I I to a pulley I I2 fixed to a rotatable sleeve I I3 that is mounted upon bearings II4 within the housing 31. This sleeve II3 transmits its rotational movement to eration. As shown, the motor I20 carries a pulley I2I having a belt connection I22 to a pulley I23 mounted on a shaft I24 which carries also a worm 4 I25. The worm meshes with a worm gear I26 which is fixed to a shaft I21 that extends longitudinally of the machine. The shaft I21 has fixed to it at each end a cam I28 which serves to actuate a spindle feeding mechanism, and also has connected to it a series of contactor drums I30 by which the motors IIO are energized. One of the drums I30 serves to control the stopping point of the motor I20 so that the shaft I21 will make one revolution and will then be brought to rest automatically.

As shown particularly in Fig. 8, the cam I28 is of box form and is provided with a groove I30 within which the pin end I3I of a lever arm I32 engages. This arm I32 is part of a lever structure I33 which is pivotally mounted on a pin I34" supported in brackets I35 projecting from the machine bed I0. The lever structure I33 carries also a pair of projecting arms I31 which terminate in pivot blocks I38 engaged by the yoke ends I40 of spaced vertically movable rods I which are slidably mounted in the machine bed. These rods I have attached totheir upper ends a box-like frame I44 which comprises horizontally extending spaced parallel bars I45 within which a slide block I41 is received. This slide block is pivotally mounted upon a stud I48 which is adjustably attached to a lever arm I49 having a hub portion I50 fixed to a rock shaft I.5I. This rock shaft is mounted in bearings carried by the housing 31 and projects therethrough; having attached to it within the housing a forked lever I53. The free end of the lever I53 is connected to a yoke I55 which forms part of a shifting collar I56 that is fixed to the axially movable sleeve II6. This sleeve H6, in addition to being supported within the tube I I3, has additional support in the bearing I60. I

The sleeve H6 is adjustably connected to the driving member 84 for transmission of theretational forces of the sleeve I I3 as well as the axial movement of the sleeve II6 to the spindle bar 80. To permit axial adjustment of the bar 80, to which the member 84 is attached, the exposed end of the sleeve I I6 is interiorly threaded at I65 for threaded engagement with the end I65 of the driving member 84. Rotational move- "ment of the member 84 relatively to the sleeve II6 results in axial movement of the tool carrying bar 80 relatively to the shifting collar I56. by which feeding movement is imparted to the bar 80. A look nut I61 is provided so that upon rotating the bar '84 relatively to the sleeve II6 to a position to provide for proper positioning of the boring tool, the nut I61 may be locked tight to provide a secure driving engagement. To permit of ready movement of the bar 84 and to limit 45 the inward adjusting travel thereof a projecting end member I69 is attached to the end of the bar 84.

-Manual control of the operation of the machine chucks is provided by a pair of levers.2II and 2I2 which serve respectively to actuate the hydraulic cylinders 50 of the jaw engaging mechanism of the chucks II and I2. Associated with the levers are a pair of push buttons 2| 3 and 2 I 4 for energizing the controls whereby the motor '55 I 20 is started. The manner of chucking a work piece as indicated by the numeral 30 is to insert the piece through the opening 25 of the drum so that the gear 32 stands within the jaw opening of the chuck II. While-held in approximate alignment by the operatonchuck I2 and its associated parts are moved axially into engagement with the opposite gear 32 of the assembly by rotation of the hand wheel 220 which is geared to the rack 22I fixed to the tube 35 of the chuck I2. Uponbringing the chuck I2 into engaging position over its respective gear the operator moves lever 2I2 and; due to a mechanical interconnection, simultaneously moves lever 2 to admit hydraulic pressure to both cylinders 50 for 70 simultaneous engagement of the jaws of both chucks II and I2. 7

To provide for accurate chucking of the gears pin rings are provided for assembly to the gears before chucking. A ring comprises a fiat ring like member 225 from which pins 226 project perpendicularly on about the pitch line of the gear. The pins are rather loosely held by the ring and are so spaced that they may be received between the teeth of the gear which is to be chucked. The pins are accurately ground to such a diameter that they engage the gear teeth on the pitch line and, as they extend beyond the face of the teeth, they provide an engaging surface for the chuck jaws which permit the gears to be so held that the gear pitch line is accurately and concentrically positioned with respect to the axis of rotation of the spindle bar 80.

As shown, the turning axle 230 of the operating lever 2I2 has a jaw member 23I which overlies the jaw member 232 of the shaft 233 upon which the lever 2II is mounted. This arrangement of parts permits simultaneous actuation of the chucks when the lever 2I2 is moved due to the interengaging faces of the members 23I and 232; also it permits independent release of the chucks inasmuch as movement of the lever 2I2 to its original position does not result in movement of the lever 2. Each shaft 230 and 233 carries an extending plate 235 which, in the disengaged position of the chuck control levers, serves to cover the starting buttons 236 of the switches 2I3 and 2I4. These plates serve as safety guards and prevent starting of the machine except when the chucks are in work engaging position.

Upon moving the lever 2I2 so that the work is securely held by the chucks, the operator then depresses starting button 236 of the switch 2I4 to set the driving motor I20 into operation. This causes rotation of the shaft I21 whereupon contacts are closed at the contactors I30 to start the motors IIO to rotating. Also, upon rotation of the shaft I 21, the cams I28 are rotated to cause a reciprocating movement of the frames I44 for the required feeding movement of the tool spindles. As shown in Fig. 2, the spindles are in the extended position which corresponds to their positioning upon the completion of a cut and prior to return of the spindles to their initial position. This same positioning is also shown in Figsr'l, 8, and 9. The extent of the contacting portions of those contactors which control the motors H0 is such that when the cam I28 reaches the position of maximum forward travel (as shown in Fig. 8) the motors I I0 are re-energized and at the same time a brake 240 engages the brake drum 2 of each driving sleeve I I3 to'quickly bring each spindle to rest. The cams continue on in their movement so that the tools are brought back to starting position (as shown in Fig. 5) while the tools are at rest. The driving motor I20 is brought to rest when the proper contactor of the group I30 reaches a point which breaks the circuit of the control mechanism.

Adjustment of the feeding travel of each spindle is provided by varying the length of lever arm I49. This is accomplished by moving the pin I48 to provide a lever arm of such length that when moved angularly by the reciprocating travel of the frame I44, the pivotal movement of the shaft I5I and lever I53 will be such as to impart to the sleeve IIS and drive member 84 the desired axial movement; The reciprocatory travel of each frame I44 is constant as determined by the shape of the cam slots I30. The extent of inward movement of the tool spindles by the cams I28 is also fixed as the tool spindles are in their extreme forward feeding position when the adjusting slot for the pin I48 lies parallel to the guides I45 of the frame I44 and consequently is the same regardless of the length of lever arm. Outward movement of the spindles, that is, away from one another, may be varied by changing the setting of the pin I48, and this is provided by loosening the nuts 244 and sliding the block 245 along theslot 246 provided in the lever'arm I49.

This machine is primarily intended for operating on large quantities of like parts so that generally a great many work pieces will be run through the machine before a change in setting is made to accommodate different kind of work piece. To insure the desired high degree of precision'in the work, it is of advantage, when changing the machine to operate on a diiferent kind of work piece, to provide a different tool carrier having a desired length of sleeve portion which will permit the cutting tool to travel inwardly for the desired length of cutting travel while properly supported, and will permit it to be withdrawn an amount suflicient to pass beyond the end of the work piece for its insertion and withdrawal. The proportioning of the spindle bar 80 is such that in its extreme inward positioning of feeding travel, toward the work, the forward end of the bar does not project beyond the cylindrical bore I9 of the sleeve I5 which supports it. Such an arrangement permits an accurate boring operation as the distance from the tool I12 to its support, as determined by the forward end of the bar 80 is always constant. This limiting of the bar travel to with- -in theconfines of its support eliminates any tendency toward c'onical boring. When the tool hasa variable overhang such as results when the bar 80, at the position of inward feeding movement, projects beyond the inner face of the sleeve I5 and thus changes the distance from the tool to its support so that it is greater at the position of maximum feeding movement than when the tool is withdrawn or is just entering the cut the difference in the unsupported length from the tool to the sleeve 51 is suflicient to cause the tool to make a tapered cut. This condition of constant overhang becomes a very important factor when it is considered that the boring limits are frequently within a tolerance of three ten-thousandths of an inch and that a tool improperly supported by having variable overhang might easily bore a hole which is conical beyond the limits of tolerance.

Upon completing the boring operation, and

after the machine has come to rest, the operator moves the lever 2I2 to its original position thus releasing the jaws of chuck I2 so that this chuck and its associated parts may be moved axially away from the work piece. The operator then grasps the work piece 30 and releases the lever 2I I for disengagement of the jaws of chuck II whereupon the completed piece may be removed from the machine. Simultaneous engaging movement causes the work piece to be accurately engaged in proper position without possibility of misalignment due to one setof jaws engaging before the other set acts and thus cooking the work piece within the machine Independent disengaging permits withdrawal of one chuck before the piece is released for removal.

If desired, this machine tool may be operated as two independent machines in which case the interfitting members 23I and 232 are disengaged and rendered inoperative, so as to permit such operation, orthe machine may be used in such a manner that only one chuck is in service and the spindles are actuated alternately. The illustrated' embodiment of the invention shows the operation of the machine on a cluster gear in which spaced bushings are bored simultaneously in a manner resulting in accurate alignment of the finished faces of the bushing. When so operating the machine the control mechanism is connected so that both chucks engage upon actuating the lever 2| 2, and both motors I I0 are started by the contactors I30 upon putting the motor I20 in operation by closing the switch button 236. When it is desired to have the machine operate as two independent units, it is only necessary to remove the interconnection between the levers 2| I and H2, and remove the safety latch 250 from the switch 2 and move the control arm 25! to an opposite position whereby switches H3 and 2 are rendered independently operative. If, for example, a single gear having a single bushing is to be operated upon, the work may be inserted within chuck H operating as an independent unit so that only the boring tool of chuck ll operates upon setting the machine into motion by actuating the starting switch 2I3. If it is desired to operate on a single gear having spaced concentrically related bushings the machine may be adjusted by provision of proper cams I28 and suitable contactors I30 to cause the spindles to operate alternately in which case the work piece would be engaged in chuck H and upon setting the machine into operation first one spindle would take its feeding cut and would return followed by a feeding cut of the opposite spindle and its return.

When the machine is used for boring bushings, tool bits such as tungsten carbide or some other suitable material which permits a high cutting speed is used. The combination of this high cutting speed, about 3000 R. P. M., togetherwith a relatively light cut, about five thousandths of an inch, results in a finish being imparted to the bushings which is sufficiently smooth as to require no further processing. By holding the work piece stationary and rigid with respect to the tool'spindies any stresses which would tend to cause distortion as a result of the rapidly rotating parts is readily controlled in the relatively light weight and easily balanced tool spindle parts. By providing this rigid assembly of sturdy members which are securely and accurately maintained in operating alignment, the machine is capable of quickly traversing its cycle of operation and of producing work which is accurate to a high degree of precision; something which has heretofore been considered impossible of accomplishment in previous machines in which the work piece and necessarily heavy work holding means have been made the rotating parts.

While the form of apparatus herein described constitutes a preferred embodiment of the inventionyit is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

l. A machine tool of the character described, comprising a machine bed, spaced axially aligned non-rotatable work receiving members mounted on said bed, work engaging means on said work receiving members, and means for actuating said work engaging means comprising an independent control handle for each work receiving member, means interconnecting said handles for simultaneous actuation of the work engaging means of both receiving members to work engaging position by manual actuation of one handle in one direction, said interconnecting means being inoperative upon movement of said handle to the release position of the work engaging means for independent movement of the handles to release 6 position.

2. In a machine tool of the character described, spaced axially aligned non-rotatable chucks, a tool spindle assembly mounted in each of said chucks, each of said spindle assemblies compris- 10 ing a sleeveand a rotatable and axially movable tool carrying spindle slidably mounted therein and having a normal positioning in the sleeve in which the spindle end stands a distance from the sleeve end greater than the axial movement of 15 the spindle, means for supporting a tool from each of said tool carrying spindles at a fixed distance from the spindle end, means for moving said tool spindles simultaneously, the extent of travel being limited to that in which the end portions are retained within the sleeves to provide a tool support of fixed length in all positions of the spindles.

3. In a machine tool of the character described, means for holding and operating upon a work piece comprising a chuck, jaws and actuating 25 means therefor, a sleeve fixed to and extending from said chuck on the axis thereof, and a spindle assembly comprising a stationary tubular member and a spindle movable therein and adapted to carry a tool, said stationary tubular member being 30 received within the chuck sleeve and closely held at the end adjacent the chuck, and means on the sleeve effective on the end of the tubular member remote fromthe chuck for angular adjustment of the spindle assembly with respect to the chuck 35 axis.

4. In a machine tool of the character described, means .for holding and operating upon a work piece comprising .a chuck, jaws and actuating means therefor, a sleeve fixed to and extending from said chuck on the axis thereof, and a spindle assembly comprising a stationary tubular member and a spindle movable therein and adapted to carry a tool, said stationary tubular member be ing received within the chuck sleeve and closely 45 held adjacent one end by the chuck and sleeve, the opposite end of the tubular member being loosely received within the sleeve, and angularly spaced adjusting screws on the sleeve extending perpendicularly to the chuck axis and adiustably engaging the tubular member adjacent the end remote from the chuck for angular adjustment of the spindle assembly with respect to the chuck axis.

5. In a machine tool of the character described, 55 a rotatable and axially movable tool carrying spindle, driving means therefor axially spaced from said spindle and comprising a rotatable member, a sleeve slidably mounted in said rotatable member and in drive transmitting relationship therewith, means for axially moving said sleeve, a connecting member extending through said sleeve, a flexible coupling attaching said con-, necting member to said tool carrying spindle for transmission of movements thereto, and means 65 at the end of the connecting member remote from the spindle adjustably attaching said connecting member to said sleeve whereby the positioning of said spindle may be varied with rmpect to the positioning of said sleeve and sleeve moving means, said adjustable attachment being adjacent the end of the sleeve remote from the s indle.

RAY I. MARTIN.

CERTIFICATE OF CORRECTION.

Patent No. 2,015,685. October 1, 1935.

RAY I. MARTIN.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, Second column, line 24, for "assembled" read assembly; and page 4, first column, line 51, for "re-energized" read de-enerized; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office Signed and sealed this 5th day of November, A. D. 1935.

Leslie Frazel (365i) Acting Commissioner of Patents. 

